1. Field of the Invention
This invention relates to a disc cartridge for housing a disc-shaped recording medium, such as an optical disc or a magneto-optical disc, loaded on a recording and/or reproducing apparatus. More particularly, it relates to a disc cartridge in which a shutter mechanism adapted for opening or closing an aperture formed in a main cartridge body unit is made up of two shutter members adapted for being moved along the major surface of the main cartridge body unit.
2. Description of the Related Art
There has hitherto been used a disc cartridge housing an optical disc, a magneto-optical disc or a magnetic disc and which is loaded therewith on a recording and/or reproducing apparatus.
As this type of the disc cartridge, there is known such a device described in the U.S. Pat. Nos. 4,510,546 and 4,876,619.
With the disc cartridge described in these publications, a disc as a recording medium is rotationally housed within a main cartridge body unit which is rectangular in shape. The main cartridge body unit has a recording and/or reproducing opening for allowing a portion of the housed magnetic disc to be exposed to outside across the inner and outer rims of the disc. This main cartridge body unit carries a shutter member, rectangular in cross-section, adapted to be moved along the front side of the main cartridge body unit for opening/closing the recording and/or reproducing opening.
With the disc cartridge, carrying the shutter member for opening/closing the opening formed in the main cartridge body unit, the opening is perpetually kept closed by the shutter member to prevent affixture of a fingerprint of a user inadvertently touching the recording surface of the disc or to prevent intrusion of dust and dirt via the opening to assure reliable disc protection.
As a disc cartridge housing a disc as an information recording medium, there is known such a one as described in the U.S. Pat. No. 4,614,990.
In the disc cartridge described in this Publication, a shutter member is provided in parallel with the inserting direction of the disc cartridge into the recording and/or reproducing apparatus, so that, on insertion of the disc cartridge into the recording and/or reproducing apparatus, the shutter member is locked or unlocked by an unlock mechanism provided on the recording and/or reproducing apparatus, at the same time as the shutter member is moved in a direction of opening the opening, with the result that the shutter member can be opened or closed by a simplified mechanism.
As a disc cartridge housing a disc as an information recording medium, there is known such one as disclosed in the U.S. Pat. No. 5,570,252. The disc cartridge disclosed in this Publication has an opening in a lateral surface of the main cartridge body unit. The magnetic head is introduced via this opening into the inside of the disc cartridge into sliding contact with the signal recording region of the magnetic disc. In this disc cartridge, the shutter member adapted for opening/closing the opening is mounted for performing movement along a lateral side of the main cartridge body unit.
Meanwhile, with the disc cartridge disclosed in the U.S. Pat. Nos. 4,510,546 and 4,876,619, in which the shutter member is moved along the outer surface of the main cartridge body unit, dust and dirt tend to become affixed to the surface of main cartridge body unit along which slides the shutter member. The dust and dirt, thus deposited, tend to drop into the inside of the main cartridge body unit with movement of the shutter member, thus contaminating the disc housed in the main cartridge body unit.
Also, since the shutter member is moved in a direction perpendicular to the inserting direction of the disc cartridge into the recording and/or reproducing apparatus, it is necessary to provide a complex opening/closing mechanism, such as a rotary arm, thus complicating the mechanism of the recording and/or reproducing apparatus.
Similarly, with the disc cartridge disclosed in the U.S. Pat. No. 4,614,990, in which the shutter member is moved along the outer side of the main cartridge body unit, dust and dirt tend to become affixed to the surface of the main cartridge body unit along which the shutter member is moved, so that the dust and dirt tend to drop into the inside of the main cartridge body unit to contaminate the disc housed in the main cartridge body unit.
In the disc cartridge disclosed in the U.S. Pat. No. 5,570,252, in which the magnetic head is inserted into the inside of the main cartridge body unit via the narrow opening provided in the lateral side of the main cartridge body unit, there are imposed limitations on the recording and/or reproducing mechanism used. Such disc cartridge is extremely difficult to apply to an optical disc used in an optical pickup device. Moreover, the shutter member is configured for opening/closing the opening which is narrow in width and longer in length than in width, the shutter member is also narrow in width and longer in length to render it difficult to realize stable movement of the shutter member.
It is therefore an object of the present invention to provide a disc cartridge in which it is possible to prevent dust and dirt deposited on the outer surface of the main cartridge body unit in association with movement of the shutter member from being intruded into the inside of the main cartridge body unit to assure reliable protection of the disc-shaped recording medium housed in the main cartridge body unit.
It is another object of the present invention to provide a disc cartridge having a shutter mechanism including a recording and/or reproducing opening larger in size than the main cartridge body unit housing the disc-shaped recording medium to enable use of the large-sized recording and/or reproducing mechanism to permit the large-sized opening to be opened or closed reliably.
It is still another object of the present invention to provide a disc cartridge that is able to close the opening in the main cartridge body unit reliably to protect the disc-shaped recording medium housed in the main cartridge body unit reliably.
It is yet another object of the present invention to provide a disc cartridge reduced in thickness and a recording and/or reproducing apparatus employing the disc cartridge and which is also reduced in thickness.
A disc cartridge according to the present invention is such a disc cartridge housing a disc-shaped recording medium such as an optical disc or a magneto-optical disc and which is loaded along with the disc-shaped recording medium on the recording and/or reproducing apparatus. A shutter mechanism for opening/closing an opening provided in the main cartridge body unit includes two shutter members movable along the major surface of the main cartridge body unit. An area in which are moved the first shutter member and the second shutter member of the main cartridge body unit is constituted by first and two wall sections arranged facing each other. The first and second shutter members are intruded into a spacing defined between the first and two wall sections.
The disc cartridge includes a main cartridge body unit and first and second shutter members. The main cartridge body unit rotatably houses the disc-shaped recording medium, and includes first and second wall sections facing the portion of the disc cartridge in turn facing the major surface of the disc-shaped recording medium at a pre-set separation from each other. The main cartridge body unit also includes a recording and/or reproducing opening facing the first and second wall section for exposing a portion of the signal recording region of the disc-shaped recording medium to outside and a driving opening adapted to allow the center of the disc-shaped recording medium to be exposed to outside. The first and second shutter members include first and second shutter members adapted for opening/closing the recording and/or reproducing opening and the driving opening. The first and second shutter members are adapted to be moved between the first and second wall sections.
The first shutter member is supported so that its one end will be moved along the position proximate to the outer rim of the circular medium housing section formed on the main cartridge body unit for rotationally housing the disc-shaped recording medium. The second shutter member is supported by the main cartridge body unit in association with the rotation of the first shutter member by having its portion engaged and held by the engagement holding portion provided on the first shutter member.
Another disc cartridge according to the present invention is such a disc cartridge rotationally housing a disc-shaped recording medium in a main cartridge body unit made up of an upper half cartridge and a lower half cartridge abutted and connected to each other. The disc cartridge includes a recording and/or reproducing opening provided in the main cartridge body unit for exposing a signal recording region of the disc-shaped recording medium at least across the inner and outer rims of the disc-shaped recording medium, a driving opening for entrance of the rotating driving means for the disc-shaped recording medium and a shutter mechanism for opening/closing the driving opening. The shutter mechanism provided on the disc cartridge includes a first shutter member for opening/closing mainly the recording and/or reproducing opening and a second shutter member for opening/closing mainly the driving opening. The first shutter member includes a shutter portion for opening/closing the recording and/or reproducing opening and the driving opening, a movement causing portion for causing movement of the shutter portion and a connecting portion interconnecting the shutter and movement causing portions. The movement causing portion is moved along a lateral surface of the disc cartridge to move the shutter portion to open/close the respective openings.
The disc cartridge according to the present invention also includes a main cartridge body unit and a shutter member. The main cartridge body unit has a recording medium housing section for housing the disc-shaped recording medium therein, a first wall section constituting the bottom wall of the medium housing section, a second wall section arranged facing the first wall section, a second opening formed in the second wall section for facing the first opening formed in the first wall section, a cut-out formed in the peripheral wall of the recording medium housing section and a groove formed in continuation to the cut-out. The shutter member includes a shutter portion arranged between the first and second wall sections for opening/closing an opening comprised of the first and second openings and a cut-out opening/closing portion arranged in adjacency to the shutter portion for extending from the cut-out to the groove for opening/closing the cut-out. The cut-out opening/closing portion is stepped in shape.
Other objects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments and the claims.